Like the thread title says, I have a slow leak somewhere in the air system in my T/L/Backhoe. I have verified that the one way check valve between the air tank and compressor is not allowing any air to back-feed to the compressor. I have installed two new air brake chambers. One of them was leaking. I did find one air line with a tiny leak in it and replaced it. I am still loosing air somewhere in the system. I tried soapy water but, there are nearly inaccessible places I cannot use it effectively. Has anyone put freon in an air-brake system and used a freon detector to locate leaks ? Is that a bad idea ? I found freon detectors on Ebay for about $25.00.
I on my wheel loaders the brake pedal valve leaks due to some dirt/rust in the lines. I pull them apart cleaned them out and it stops the leak. Check those valves.
Freon not cheap, air is free, I would hook up a air line from garage or service truck to supply line coming of your air compressor, that way you can maintain air without having engine running, then go back to listening, does gauge drop when you step on brake, off brake , release parking brake, act, does it have a air drier, rotted out tank, leaking drain, air wipers, air horn, neutral lockout? Sometimes its tough, sometimes a second person will hear differently and can pick a leak out.
I installed a quick coupler into the air line at the compressor some time ago to supply shop air into the system. I have listened with a hose to my ear quite a bit. It looses air constantly,engine on or off. It is a small leak and takes about 20 minutes to empty the system with the engine off. It doesn't matter if the parking brake is on or off which leads me to think it is somewhere in front of the foot pedals and parking brake valve. The foot pedal valves have been overhauled with kits. I suppose I should check them again. There is no air drier. The tank is solid. No air wipers or horn, just a braking system. I need to check the tank high pressure relief valve. I wasn't thinking of completely replacing all the air in the system with freon, maybe one can. I installed the second new air brake chamber yesterday although it showed no signs of leakage. I will replace the lines to it tomorrow with new ones. many of the original lines are still on the machine. I was able to buy new brake chambers cheaper than a local heavy truck repair shop would charge to overhaul the old ones.
Had to do this just a couple days ago. Went through three guys till I found one who could hear it! He could not understand why we could not, but then he is only in his midtwenties the rest of us ranged from mid fifties to mid sixties. So find the youngest guy to help you.
That is a problem. I am in my early seventies ! But, fortunately my hearing is still decent. I will probably enlist the help of a grandson this weekend. For what it is worth I just edited my last previous post to include more info.
I've had some air tanks get a a hairline crack right around the mounting bracket that is hard to see. The tank looked solid otherwise. I pulled the tank off, ground out the crack, welded, then plugged the extra holes in the tank, installed a ball valve and shot it full of shop air and checked with soapy water. Just make sure that if u still have a leak, you dump the air before you go back to welding....blow a hole in the tank with 120psi of air in it and it becomes a underwear changing experience. Good luck
I'm taking that from this you don't mean you hear air at this quick coupler. At first read I thought that's what you wrote!
Is the seat an air ride item? tctractors
No leak at the quick coupler. After I installed it, I ran a new hose to the air tank. I have been using a hose and hold it close to my ear. It works quite well for finding noises of any kind. No tc , it doesn't have an air-ride seat. Just an air brake system. I am going to start replacing all the old original hoses that came on the tractor when it was new. I will take a close look at the air tank. The tractor is thirty years old, but in excellent condition considering its age.
Air systems are a hard one. I once spent two days on a truck and couldn't get it to hold air for more than a few hours. Sometimes it's just the way it's going to be. Have you tried tightening all the connections?
Not yet Shimmy. I was hoping to find the leak before doing that. There are a lot of connections and some are in very hard to get at places.
Disconnect and cap the lines going to the foot pedals and parking brake valve. If the leak stops or significantly slows, reconnect one at a time to identify the guilty party. Air systems are not meant to be completely leakproof as engineers will point and say "look, it has a compressor that replenishes your air supply constantly". On the other hand I would expect a properly functioning system to hold air for at least a couple hours.
I will do that next week, hopefully. I have an eye infection right now and can't risk getting anything in it.
This is an update to my air leak search. I have finally found it. The air compressor discharge goes directly to the air tank. There is a one way check valve located in that line right at the tank. It is leaking and allowing air to go back to the compressor. I ran the engine until the system was up to 125 psi. I then shut off the engine and removed the the hose on the compressor inlet. I put my thumb over the inlet port and found that air was coming out of it. That is one leak that a person would never be able to find by listening for it. The reason being is that the air compressor pulls filtered air out of the engine air cleaner. I am now trying to find a replacement check valve.